1. Field of the Invention
The present invention relates to an ophthalmologic apparatus.
2. Description of the Related Art
A scanning laser ophthalmoscope (SLO), which is an ophthalmologic apparatus utilizing a principle of a confocal laser microscope, can perform raster scanning on, for example, a fundus of a subject's eye with a laser that is measurement light, and obtains a planar image from intensity of its return light from the subject's eye with high resolution at a high speed. Such an apparatus for capturing a planar image is referred to as SLO apparatus in descriptions below.
There is known a technology for measuring aberration caused by a subject's eye by a wavefront sensor in real time, and correcting the aberration caused by the subject's eye by a wavefront correction device. Japanese Patent Application Laid-Open No. 2010-259543 discusses an adaptive optics SLO (hereinafter, may be referred to as AOSLO apparatus) including an adaptive optical system for correcting the aberration by the wavefront correction device. This technique enables the adaptive optics SLO to obtain a planar image of high lateral resolution (See Japanese Patent Application Laid-Open No. 2010-259543). By continuously capturing the planar image via the above-described AOSLO apparatus, a flow of blood cells (blood flow rate) in a fundus blood vessel can be recorded. In addition, the number and shapes of visual cells can be measured from a fundus visual cell image in a certain area.
To accurately record the blood flow rate, an imaging frame rate is faster, the better. In addition, as an imaging range for measuring the visual cells is wider, images more useful for diagnosis can be obtained.
However, when the frame rate or the imaging range is set to an arbitrary value, there is a possibility that signal intensity obtained by a detector will be deteriorated depending on the characteristics of the detector, such as frequency characteristics, used for imaging.